Load control module

Abstract

A load control module suitable for an electrical equipments driven by an operation of a switch is disclosed. The load control module includes an energy storage unit, a signal transforming unit, a first control unit and a second control unit. The energy storage unit still outputs a reserved voltage for a predetermined time during the switch is turned off. The signal transforming unit and the first and the second control unit are driven by the reserved voltage. With a different switching speed of the switch, the second control unit may operate in coordination with the actions of the signal transforming unit and the first control unit to regulate a level of the control voltage, or maintain the level of the control voltage in a current state. The electrical equipments may perform diversified control functions under control of the load control module operated in coordination with an operation of the switch.

1. A load control module, for an electrical equipment, wherein the electrical equipment is controlled by an operation of a switch, the load control module comprising:
 an energy storage unit, for converting a supply voltage and outputting a reserved voltage when the switch is turned on, and continuously outputting the reserved voltage for a predetermined time when the switch is turned off; 
 a signal transforming unit, coupled to the energy storage unit, and driven by the reserved voltage, configured to transform the supply voltage output from the switch into a counting signal; 
 a first control unit, coupled to the energy storage unit and the signal transforming unit, and driven by the reserved voltage, configured to filter and rectify the counting signal to output a rectified signal, wherein when a level of the rectified signal is switched to a second level, the first control unit latches the level of a clamping signal to the second level, and until the first control unit is reactivated, the first control unit then outputs the clamping signal having a first level; and 
 a second control unit, coupled to the energy unit, the signal transforming unit, the first control unit and the electrical equipment, and driven by the reserved voltage, configured to output a control voltage to control characteristic parameters of the electrical equipment, 
 wherein when the second control unit receives the clamping signal having the first level, the second control unit counts continuously in response to the counting signal, so as to adjust the level of the control voltage according to a counting result, and when the second control unit counts up to a predetermined value or receives the clamping signal having the second level, the second control unit stops counting, the level of the control voltage is switched to one of a plurality of predetermined levels according to an inverted signal of the rectified signal. 
 
   
   
     2. The load control module as claimed in  claim 1 , wherein the second control unit comprises:
 a frequency divider, coupled to the signal transforming unit, configured to divide a frequency of the counting signal into a specific frequency to output a square wave signal when the frequency divider is activated; 
 a counting unit, coupled to the frequency divider and the first control unit, configured to count an accumulated value up to the predetermined value according to the square wave signal when the counting unit is activated, wherein when the counting unit counts up to the predetermined value or receives the clamping signal having the second level, the counting unit stops counting and generates an interrupt signal having the second level; 
 a rough adjusting unit, coupled to the counting unit and the first control unit, determining to output one of a plurality of predetermined level adjusting values according to the inverted signal of the rectified signal and the interrupt signal, so as to generate a specific adjusting value and a control signal, when the rough adjusting unit is activated, wherein the level adjusting values respectively correspond to the predetermined levels; 
 a multiplexer, coupled to the counting unit and the rough adjusting unit, configured to output the specific adjusting value when the multiplexer receives the control signal, and conversely, output the accumulated value; and 
 a digital-to-analog converter, coupled to the multiplexer, configured to output the control voltage, and convert the level of the control voltage according to the accumulated value or the specific adjusting value, when the digital-to-analog converter is activated, 
 wherein the frequency divider, the counting unit, the rough adjusting unit, the multiplexer and the digital-to-analog converter are respectively coupled to the energy unit, and are driven by the reserved voltage. 
 
   
   
     3. The load control module as claimed in  claim 2 , wherein the second control unit further comprises:
 a buffer, coupled to the energy storage unit, the digital-to-analog converter and the electrical equipment, and driven by the reserved voltage, configured to buffer and output the control voltage when the buffer is activated. 
 
   
   
     4. The load control module as claimed in  claim 2 , wherein the counting unit comprises:
 a counter, coupled to the energy storage unit and the frequency divider, and driven by the reserved voltage, configured to count the accumulated value up to the predetermined value according to the square wave signal when the counter is activated, and generate a state signal having the first level when counting up to the predetermined value; and 
 a first AND gate, for receiving the clamping signal and an inverted signal of the state signal to generate the interrupt signal, 
 wherein when the interrupt signal has the second level, the counter stops counting. 
 
   
   
     5. The load control module as claimed in  claim 2 , wherein the rough adjusting unit comprises:
 a second AND gate, for generating an enable signal when the interrupt signal and the inverted signal of the rectified signal have the first level; and 
 a level selector, coupled to the energy storage unit and the second AND gate, and driven by the reserved voltage, configured to select one of the level adjusting values to be the specific adjusting value according to the enable signal when the level selector is activated, so as to generate the control signal. 
 
   
   
     6. The load control module as claimed in  claim 1 , wherein the energy storage unit further outputs a first reset signal during high transition of the reserved voltage, and outputs a second reset signal when the level of the reserved voltage drops to a threshold value, wherein the first control unit switches the level of the clamping signal to the first level according to the first reset signal, and the second control unit is reset according to the first reset signal or the second reset signal. 
   
   
     7. The load control module as claimed in  claim 6 , wherein the energy storage unit comprises:
 a first diode, with an anode of the first diode coupled to the switch; 
 a first resistor, with a first end of the first resistor coupled to a cathode of the first diode; 
 a second resistor, with a first end of the second resistor coupled to a second end of the first resistor, and a second end of the second resistor coupled to the ground; 
 a first capacitor, with a first end of the first capacitor coupled to the second end of the first resistor, and a second end of the first capacitor coupled to the ground; 
 a regulator, coupled to the first end of the second resistor, configured to output the reserved voltage; and 
 a reset circuit, coupled to the regulator, for detecting a level of the reserved voltage, so as to output the first reset signal during the high transition of the reserved voltage, and output the second reset signal when the level of the reserved voltage drops to the threshold value. 
 
   
   
     8. The load control module as claimed in  claim 1 , wherein the first control unit comprises:
 a filtering rectifier unit, coupled to the signal transforming unit, for filtering and rectifying the counting signal to output the rectified signal; and 
 a latching unit, coupled to the energy storage unit and the filtering rectifier unit, for outputting the clamping unit according to the rectified signal when the latching unit is activated, wherein when the level of the rectified signal is switched from the first level to the second level, the latching unit latches the level of the clamping signal to the second level, until the latching unit is reactivated. 
 
   
   
     9. The load control module as claimed in  claim 8 , wherein the filtering rectifier unit comprises:
 a second capacitor, with a first end of the second capacitor coupled to the signal transforming unit; 
 a third resistor, with a first end of the third resistor coupled to a second end of the second capacitor, and a second end of the third resistor coupled to the ground; 
 a second diode, with an anode of the second diode coupled to the second end of the second capacitor; 
 a third capacitor, with a first end of the third capacitor coupled to a cathode of the second diode, and a second end of the third capacitor coupled to the ground; 
 a fourth resistor, with a first end of the fourth resistor coupled to the cathode of the second diode, and a second end of the fourth resistor coupled to the ground; and 
 a fifth resistor, with a first end of the fifth resistor coupled to the cathode of the second diode, and a second end of the fifth resistor being used for outputting the clamping signal. 
 
   
   
     10. The load control module as claimed in  claim 8 , wherein the latching unit comprises:
 a third diode, with an anode of the third diode coupled to the energy storage unit; 
 a second Schmitt trigger, coupled to the energy storage unit, the filtering rectifier unit and a cathode of the third diode, and driven by the reserved voltage; 
 a third Schmitt trigger, coupled to the energy storage unit and the second Schmitt trigger, and driven by the reserved voltage; 
 a fourth diode, with an anode of the fourth diode coupled to the second Schmitt trigger; and 
 a sixth resistor, with a first end of the sixth resistor coupled to the cathode of the third diode, and a second end of the sixth resistor couple to the third Schmitt trigger. 
 
   
   
     11. The load control module as claimed in  claim 1 , wherein when the supply voltage is an AC signal, the signal transforming unit comprises:
 a filter, for filtering a noise of the supply voltage; and 
 a first Schmitt trigger, coupled to the energy storage unit and the filter, and driven by the reserved voltage, configured to covert the filtered supply voltage into the counting signal. 
 
   
   
     12. The load control module as claimed in  claim 1 , wherein when the supply voltage is a DC signal, the signal transforming unit is a voltage-controlled oscillator, and the voltage-controlled oscillator is coupled to the energy unit, and is driven by the reserved voltage.